Chapter XXII: Section III: Local Position of the Several Mines

Since the first discovery of lead in this Territory, the number of mines has been much increased, and hardly a season passes without some new discovery. Every discovery of importance soon becomes the centre of mining attraction. As the ore is found in the diluvial soil, it is generally exhausted on reaching the solid rock; and after penetrating a considerable area of the surface with any, or but partial success, the locality is abandoned, and a new one sought. As the mines are worked without capital, and the ore is dispersed over a wide area, the number of localities is almost indefinite. Upwards of forty principal sub-districts are known, most of which are appropriately denominated _diggings_. The earliest discovery, at Mine a Burton, has been one of the most valuable, and still continues to afford the ore. Mine a La Motte has also proved an extensive deposit, and is still unexhausted. New Diggings, Shibboleth, and Richwoods, are among the discoveries of later date, which have yielded very large quantities of ore. But the mode of mining in the diluvial soil must exhaust it of its mineral contents, and direct miners, in after years, to the true position of the ore, in the calcareous rock. So long as the search continues in the soil, the business will partake of the uncertainty which now attends it, and which renders it rather an object of temporary enterprise, than a fixed employment.

In the search for ore in the soil, scarcely any uniform principles can be certainly relied on. Generally, rocky and barren localities are avoided, and large and deep beds of the red metalliferous clay sought for. The occurrence of crystallized quartz, or spars, on the surface, is regarded only as a general indication, but cannot be depended on to ensure local success. These masses are found to be distributed on and through the top soil, as other debris, being sometimes contiguous to, and sometimes remote from, ore. But they are never, so far as I have observed, found with the ore.

The method of searching for and raising the ore, is simple. Having fixed on a spot for digging, the operator measures off about eight feet square. A pick-axe and shovel are used for removing the earth. A practised hand will pitch the earth from a depth of eight or ten feet. A windlass and bucket are then placed over the pit, and the excavation thus continued. Small detached masses of ore, or spars, are often found in the soil, in approaching a larger body. The ore is the sulphuret, or galena. It has a broad, glittering grain, and is readily divisible into cubical fragments. It occurs in beds, or detached masses, which are deposited horizontally in the soil. They are often accompanied by the sulphate of barytes, or by calcareous spar; sometimes by blende, or iron pyrites. The ore is often connected with the barytic spar, indicating the latter to be a true matrix. The direction of these beds of ore appears to be irregular. Veins of ore are confined to the rock.

The variety of ore called _gravel ore_, differs from the preceding chiefly by its marks of attrition, and connection with diluvial pebble-stones. No spars have been noticed in these gravel-beds, although it is probable that a careful search might detect them.

The calcareous spar is most abundant in connection with rock diggings. It is translucent, or transparent, and often exhibits the property of double refraction. The miners, who employ their own conventional terms, call this substance _glass tiff_, to distinguish it from the sulphate of barytes, which is denominated _tiff_. Much of the radiated quartz of this district bears the marks of diluvial action. It is not uncommon to find masses of it, in which the angles of the crystals are quite defaced. Veins of ore in the rock correspond generally, in their course, I think, with the cardinal points, in the instances of their being pursued horizontally. But they dip at various angles with the plain, or sink perpendicularly into the rock.

The horizontal position of the ore-beds in the red clay soil, may be regarded as an evidence of its being a diluvial deposit.

The metalliferous, red, marly clay, is, in fine, the most interesting geological problem connected with the mines, and is calculated to show us how little we know of the true eras of the diluvial deposits. After every examination which we have been able to make, we are decidedly of the opinion that this formation belongs to the diluvial, and not to the alluvial era. It seems, indeed, to assert a claim to be considered, among the western strata, as immediately succeeding the secondary. It lies directly next to, and upon, the limestone rock. We have witnessed the progress of an excavation on the public square of Potosi, in which the soil was removed down to the rock, and a clean area of its surface was exposed. There was no other stratum below it, and between the clay and rock. And such we believe to be its general position. The radiated quartz and pebble drift is above it, and, consequently, constitutes a subsequent deposit. And hence it is that the numerous fragmentary masses of the former, called _mineral blossom_, are no sure indications of the subterraneous presence of ore. The gravel-ore and mixed diluvial gravel is likewise a newer deposit, coinciding with the era of the primitive and secondary boulders. No large primitive boulders, however, exist in the mine district, if we except the angular fragments of granite, south of St. Michael, which are, indeed, just without the lead-yielding area. Pebbles of common quartz, granite, and greenstone, are found in the surface soil, and are also to be observed, in accumulated masses, in the beds of brooks. Occasionally an orbicular mass of these rocks, of the size of a melon, is observed. It is evident, from these appearances, that no formations of the primitive exist, towards the sources of the Mississippi, for a great distance, as it is from this direction that diluvial action appears to have been propagated. This clay soil is free from boulders, and is of a homogeneous texture. It partakes, in its qualities, so largely of marl, as to operate as a manure, on being thrown out of the pits, and, after a few years, is covered with a very rank growth of trees, vines, &c. This is a characteristic trait of the locality of abandoned diggings.

The following is a catalogue of the mines. It comprises those of most note, which are now worked, or have been at some former period.

1. Mine a Burton. 24. Tapley's Diggings.
2. Mine a Robino. 25. Lambert's Diggings.
3. Mine a Martin. 26. Old Mines.
4. New Diggings. 27. Mine Shibboleth.
5. Citadel Diggings. 28. Elliot's Mines.
6. Perry's Diggings. 29. Belle Fontaine.
7. Hawkins's Mine. 30. Cannon's Mines.
8. Rosebury's Mine. 31. Little Diggings.
9. Austin's Shaft. 32. Becquet's Diggings.
10. Jones's Shaft. 33. Mine Liberty.
11. Rocky Diggings, (Prairie de Roche). 34. Renault's Mines.
12. Gravelly Diggings. 35. Miller's Mine.
13. Brushy-run Diggings. 36. Mine Silvers.
14. Stricklin's Diggings. 37. Fourche a Courtois.
15. Bibb's Diggings. 38. Pratt's Mine, Big river.
16. Tebault's Diggings, (Pinery). 39. Lebaum's Mine, Richwoods.
17. Mine Astraddle. 40. Mine a Joe, Flat river.
18. Masson's Diggings, or Partney's. 41. Bryan's Mines, Hazel run.
19. J. Scott's Diggings. 42. Dogget's Mine, Hazel run.
20. T. Scott's Diggings. 43. Mine La Motte, St. Michael.
21. Micheaux's Diggings. 44. Gray's Mine, Big river.
22. Henry's Diggings. 45. M'Kain's Mine, Dry creek.
23. Moreau's Diggings.

The most noted mines are Mine a Burton, New Diggings, Shibboleth, Richwoods, Old Mines, and the numerous mines on the waters of the Mineral Fork of Grand river. Mine a La Motte, Mine a Joe, and Bryan's Mines, are east and south of the principal group of mines in Washington county, and at a considerable distance from them. A few general remarks may be applied to all these mines.

The mines possess one general character, although there are some peculiarities which I shall hereafter mention. The ore is found in detached pieces and solid masses, in beds, in red clay, accompanied by sulphate of barytes, calcareous spar, blende, iron pyrites, and quartz. The ore is of that kind called, by mineralogists, lead-glance, or galena, and is the sulphuret of lead, of chemistry. As it is dug up or quarried from the adhering spar, it presents a very rich appearance. It has a broad, glittering grain, of a lead-gray colour, which passes into a bluish shade. The ore is easily broken by the blow of a hammer, and may be pounded to a fine powder, still preserving its glittering appearance. In breaking it, it always separates in cubes. Sometimes detached lumps of four or five pounds weight, of a cubical form, are found imbedded in the clay. Its primitive figure of crystallization is particularly observable after the ore has been desulphurated by heat, which, at the same time, increases its splendor, and renders the lines of intersection between the facets more plainly discoverable.

The clay, or red earth, in which the ore is found, appears to partake largely of marl; and a difference of quality is to be observed at the different mines. It all, however, operates more or less as a stimulant to vegetation, on being thrown out of the pits. Mixed with the clay are innumerable pieces of radiated quartz, very beautiful in appearance. This forms the first stratum, and is about fourteen inches in depth; then succeeds a stratum of red clay, four or five feet thick, and sparingly mixed with substances of the same kind; after this, a layer of gravel and rounded pebbles, of a silicious character, ensues; these are about a foot in depth, and lead-ore, in small detached lumps, is then found. This is of the description called gravel-ore, and no spars are found accompanying it. The greatest proportion of lead-ore is, however, found imbedded in marly clay, accompanied by the sulphate of barytes, and resting on limestone rock. The rock is struck at a depth of from fifteen to twenty feet, and is a metalliferous limestone, of a semi-crystalline structure, lying in horizontal beds. It is traversed by veins of lead-ore. Sometimes these expand in the shape of caves, where masses of galena occur.

The most valuable substance accompanying the lead-ore, is an ore of zinc, which is found at several of the mines. Another substance, found with the ore in considerable quantities, is the sulphate of barytes. This is sometimes in immediate connection with the ore, but more frequently in contiguous masses, in the clay.

The sulphate of barytes, called _tiff_ by the lead-diggers here, is the same substance called _cawk_ by English miners. It is very white, opaque, and very heavy, and may be considered as the proper matrix of the lead-ore.

There are also found considerable quantities of calcareous spar, particularly in the caves and veins in rock. This substance is often observed in large orbicular or irregular masses, which have the appearance of external attrition. On breaking them, they fall into rhombs, which are very transparent and glittering; in color, they are either white, or honey-yellow.

Pyrites are common at the mines, sometimes crystallized in regular cubes of a beautiful brass-yellow color, and, at others, found in tabular masses, or mixed with blende, sulphate of barytes, or calcareous spar. Quartz is found throughout the whole mine district, both on the surface of the ground, and at all depths below. It is generally in the form of tabular pieces, whose surfaces are thickly studded over with small pyramids of transparent rock-crystal, and present an appearance of the utmost beauty and splendor, looking like so many diamonds set over the surface of white stone. These crystals are frequently grouped in the form of a hemisphere, circular, or oviform, solitary or in clusters, forming the different varieties of mamillary and radiated quartz, and, when met with in their pristine beauty, present a very rich and brilliant appearance. It has acquired the popular name of _blossom of lead_, or mineral blossom, a term perfectly significant of its supposed affinity.

The exterior stratum of red clay, with its ores and minerals, will be best understood by comparing it to a garment thrown over the rock-formations of the country. The search for ore has been generally confined to these clay diggings, which are pursued, very much, with the apparatus of common well-digging. If, on reaching the rock, no vein of ore is discovered, the work is generally dropped.

On viewing the district on a large scale, this external clay stratum appears to have originally derived its mineral contents from veins in the calcareous, lead-yielding rock. This metalliferous rock has evidently, in former ages, been scooped out by rivers and streams, forming valleys and vast diluvial plateaux, where the abraded materials were deposited. The original subterranean veins were concealed by these geological changes.

Some of the mines exhibit traits that may be mentioned. Mine La Motte is one of the oldest mines in the Territory, having been discovered in 1720, by the person whose name it bears. The mines are very extensive, and a large quantity of ore is annually raised. They are situated within two miles of St. Michael, Madison county, and on the head-waters of the river St. Francois. No spars are found accompanying the ore; iron pyrite is occasionally met with, and plumbago is found in the vicinity. The ore, which is less brilliant, and differs in other characters from any other in the mine tract, is at the same time more refractory; in some instances, the greatest difficulties have been experienced in the smelting. Hence, an idea has originated that it is combined with other metals; but no experiments, I believe, have been made to ascertain this point.

On a visit to these mines, I observed the inside of the ash-furnace beautifully tinged with a blue color of considerable intensity. This furnace is built of a white sandstone, which becomes vitrified on the surface, forming glass. We are acquainted with no substance which will communicate a blue color to glass in fusion but cobalt; hence, it is not unreasonable to infer that this metal is volatilized during the smelting, and is thus brought into contact with the liquefied surface of the stone, imparting to it the color noticed. That the ores of La Motte contain an unusual portion of sulphur, is very probable. I draw this inference both from its refractory nature and dull appearance. Sulphur always renders an ore refractory; for, when it is expelled by torrefaction, the ore melts easily. Its dull aspect is not less conclusive; for, the more an ore is roasted, and the more sulphur there is driven off, the brighter it grows. This is evident to every smelter, who cannot fail to observe the surprising brilliancy the ore assumes after it has gone through the first operation in the log furnace. That the difficulties daily experienced in smelting the La Motte ores are, therefore, attributable to the extraordinary quantity of sulphur they contain, is extremely probable; for, even if they were united with other metals, with silver or with cobalt, these would not increase their infusibility, except by the extra quantum of sulphur they brought with them. At least, we have no facts to prove that a simple alloy does not melt as easily as a pure metal, while there are many to show that alloys are of the most easy fusibility.

The quantity of ore raised at New Diggings has been very great, a regular vein having been found; but they were abandoned several years ago on account of the water, which rushed in with such rapidity, that to remove it every morning with a common windlass and bucket was found a work of such labor as to render the business unprofitable. The mines were left with the most flattering veins of ore in view. The general character of these mines is such as to justify the erection of a steam-engine, and other works for prosecuting the business on an extensive scale; and their revival at some future period may be confidently looked for.

Mine Renault is situated about six miles north-north-west of Mine a Burton, in a very rocky part of the country, which affords some of the most picturesque views of mountain scenery. The region is strongly marked by mineral appearances, rendering it probable that other substances of value, besides lead, may exist in that vicinity. Ores of zinc are abundant at this mine, and a body of micaceous oxide of iron is found in the neighborhood.

Bryan's Mines are seated on Hazel run, and are among the most recent discoveries of consequence. Near a million pounds of lead were made here during the first year of the discovery. The mine is characterized by yielding no heavy spar; sometimes a little calcareous spar is found, and then adhering to the ores; a circumstance which I have nowhere else observed. Much of the ore of these mines is found in tabular pieces, which are sonorous in a considerable degree; the ore is brilliant, and smelts readily, yielding the same as at Mine a Burton.

Gray's Mine, situated on Big river, in the northern extremity of the mine tract, is remarkable for a body of white clay, which was discovered in searching for ore. In sinking several pits at this mine, a stratum of clay of an unusual appearance was struck at the depth of from eight to ten feet, and no ore was procured at those places; the diggings were abandoned in consequence of the clay, which covers a considerable area of ground on the banks of Big river. This mineral substance bears a striking resemblance to specimens of a pyrous crucible clay.

Elliott's Mines lie upon the Mineral Fork, and are characterized by the abundance of pyrites, and the beauty of the calcareous spar found there. Considerable quantities of blende were also met with, and strong indications of the existence of copper are furnished. During the remarkable earthquakes of 1812, a fine spring of water at the mouth of the mines suddenly became warm and foul, and in a few days dried up entirely, and no water has run there since. Illuminations in the atmosphere (arising doubtless from phosphorus) are frequently observed in this vicinity on the approach of night.

At Mine a Burton, there is found adhering to the sides of the log-hearth furnace, a grayish-white sublimated matter, of great weight, which I take to be a sublimate of lead. It is considered as chiefly sulphur or arsenic by the lead-smelters, and is thrown by as useless. It is found at every furnace, and a very large quantity could be annually collected. This induced me to undertake some experiments on the subject. I was convinced, on reflection, that there could be no sulphur, at least no considerable quantity of sulphur, in it, from the fact that all sulphur, or other inflammable matter, expelled from the ore in the furnace, would undergo immediate combustion. This is also observable in the color of the flame while the ore is torrified. Indeed, every person conversant with the nature of this substance must know that it cannot be otherwise. The furnace is entirely open, and does not rise over seven or eight feet in height; consequently, there is no opportunity for it to condense. That the sulphuric acid is driven off, is undoubted; for, whenever sulphur is burned, this acid is set at liberty; but it has no opportunity for entering into a new combination within the body of a log furnace.

The idea of arsenic in the substance alluded to, is perfectly erroneous, and has originated in an ignorance of the nature of the ores of these mines. It is the _sulphuret of lead_, and not the _arseniate_. That there is a small portion of silver and antimony in combination with the ore, is probable; but they too are mineralized by sulphur. Reflecting on this, I became convinced of the popular error, and, to ascertain the point, made the following experiments:

A. I took a lump of the sublimated matter, freed from adhering impurities, and reduced it to the state of a fine powder by pulverizing in an agate mortar, and trituration. Of this I mixed six parts with four of pulverized borax, and a little charcoal, and submitted it to the intense heat of a small chemical furnace. On removing the crucible, I found a button of metallic lead in the bottom, weighing nearly four.

B. Dissolved a quantity of the powdered sublimate in nitric acid; it effected a ready solution, with violent effervescence. Poured on liquid carbonate of potash until no more precipitate fell. I then collected the precipitate, and washed away the superfluous alkali by clear water, and dried it in the shade. The result was a very fine, and a very white powder, of considerable weight. This was a carbonate of lead (white lead). With a quantity of the white lead thus made, I mixed linseed oil, and painted a board. The color was of the most delicate white, and it gave a good body. On inspecting this board several months afterwards, I found the color inclining a little to yellowish. But perhaps it stands as well as any white lead would, prepared from litharge, by solution in nitric or acetic acids, and precipitation by carbonated alkali.

C. Mixed eight parts of sublimate with twelve of muriate of soda, and fused in a crucible, with a tight cover, in a high heat. Result, a yellow, hard, heavy, vitrified mass, resembling muriate of soda and lead.

M'Kain's Mine is situated on a small stream called Dry creek, running into Big river not far from its junction with the Maramec. The mine is worthy of remark only on account of a body of steel-grained lead-ore found there. This ore is found to yield less lead in smelting than the common broad-grained ore, and, as may be inferred from its texture, contains silver.

So little has been done, of late years, in mining in the rock, that the character of the veins must be judged of from limited facts. But there can be no question, from what is known, that the true scene of mining operations is the rock.

Along the west banks of the Mississippi, and also in some of the interior valleys, we observe that the metal-bearing limestone rests on crystalline sandstone. Both preserve a horizontal position, and both are deposited, at the distance of about seventy miles south of Potosi, upon pre-existing formations of sienitic granite, embracing hornblende rock; some of the latter of which is porphyritic.

These primitive formations mark the geography of the country at the sources of the St. Francis. They form alpine peaks, through which the river forces its way. Mine a La Motte is within two miles east of this tract. These peaks have been raised to their present position without disturbing the horizontality of the limestones and sandstones. Hence the conclusion of their prior elevation.

At a still further southern point, and before reaching the banks of the St. Francis at Bettis's ferry, the horizontal rocks again appear. But, in this instance, sienitic and granitic boulders are scattered over the southern series of the calcareous strata, showing, with equal clearness, that the geological era of the boulder stratum was posterior to the deposition of the horizontal strata, and that the force which scattered the boulder stratum was from the north.